British Owls – Their Natural History and Conservation

– Chris Sperring MBE – Conservation Officer for the Hawk and Owl T rust

9^th March 2010

Chris Sperring delivered a fascinating and very interesting lecture. At the age of nine, having sat in a tree late at night, mimicking the sound of a male tawny owl, he came face to face with his quarry after a long wait! This was the beginning of a lifelong interest in nature, but a particular interest in owls. He gave short descriptions of several of our most well-known owls, barn owl, tawny owl, short-eared owl, long-eared owl and little owl.

Chris has a close working relationship with the Barn Owl Trust in Devon, and also possesses a barn owl of his own, which was rescued and is unable to be released into the wild. Barn owls are capable of breeding at any time of the year provided conditions are right. Their main source of food is voles, and the maintenance of field margins and the availability of rough grassland are therefore very important to them. They are one of the easiest owls to watch because of their light colouring. The nest sites are usually found in old buildings, ruins and in the vicinity of farms. However, the conversion of many farm buildings into dwellings has reduced the number of suitable nest sites considerably. The young are very noisy when in the nest, using a rasping hiss to beg for food or when they are disturbed. This is a sign to move away quietly and quickly because adult barn owls would rather desert their nests than attack an intruder, unlike other owl species. In 2008 Chris visited 12 barn owl boxes on the RSPB reserve at West Sedgemoor, and was very impressed with the work being carried out there.

The tawny owl is resident on mainland Britain and its preferred habitat is deciduous woodland, but they will live virtually anywhere where there are mature trees, even in parks and coniferous forests. They are nocturnal, and because they prefer to live in densely wooded areas they are difficult to see. You are more likely to hear rather than to see them. Male and female tawnies have very similar calls; the main hooting call is usually made by the male although the female will use it at a higher pitch. The screech is usually made by the female in answer to the male’s `hoooo-ho-hoooo’. Thus Shakespeare described the call as `Twit Twoo ‘ - he probably did not realise that he was listening to a pair of tawny owls!!

Short-eared owls are scarce birds, which breed in northern areas of the British Isles, predominantly on upland moorland. The open grassland habitats are their feeding grounds, where they hunt small mammals and small birds. They roost and nest on the ground in the summer and migrate south, often to southern England, for the winter, where they also roost on the ground, preferring lowland heath, coastal areas and moorland. For this reason they are easily overlooked, and if disturbed will rise from the ground and fly some distance before either returning to the ground or beginning to hunt. They are largely diurnal and can easily be observed quartering their open habitats during the day. However, when short of food they will hunt during dusk and dawn or even during the night.

The long-eared owl has a widespread, but sparse, distribution throughout the UK. In addition to the breeding birds there is also an influx of wintering long-eared owls from mainland Europe every year. They usually arrive during November and leave again by February. Their habitat is dense, coniferous woodland, surrounded by open grassland. Overwintering long-eared owls, however, tend to roost in mature hedgerows and will emerge to go hunting just before it gets dark. Breeding long-eared owls hunt during the dead of night and rarely call. When displaying, the adults will also use beak snapping and wing clapping as ways of attracting mates and declaring their territories. Their most vocal period is pre-breeding season (January-March), when both male and female call throughout the night. The baby owlets make a `squeaky garden gate’ sound when begging for food. They are very difficult birds to watch because they are strictly nocturnal, live in densely forested locations and very rarely call. It is difficult to assess exactly how scarce they are, and for this reason Chris started the first local survey on the Mendip Hills in Somerset in 1992. This began with a small group of volunteers and has grown to be a national survey carried out every year. When he finished our talk, he was off to the Haldon Forest to (hopefully) find some long-eared owls.

The little owl, now a resident, was introduced in the latter part of the nineteenth century, and is widespread in England and Wales and southern Scotland. They are a traditional farmland and parkland bird, with a liking for fruit orchards and small pasture fields with thick, mature hedgerows. River valleys are ideal places to start looking for them , especially when weather conditions are harsh, because their small size makes them vulnerable. They are mainly diurnal, but can remain active into the night when the light is good. During the winter little owls are most active in full daylight, and sometimes on a sunny day, they can be observed sunning themselves in a favoured position – a great opportunity for the photographer! The males begin their main pre-breeding calls in February when they will use their electronic sounding hoot – hoooooo – which rises in pitch during delivery. The females have a yelping call that is used by both adults during the rest of the year, which is a lower, backward version of the tawny owl screech. This can lead to a confusion of the two species. Little owls hunt for insects or small mammals and can sometimes be observed running along the ground. They also indulge in the practice of rain bathing, which involves the performance of an elaborate dance in order to ensure that the falling rain reaches every feather. This animated behaviour can be seen in other owl species, but is particularly endearing to watch in little owls. They are not as upset by rain as the other owl species because they do not require such perfectly silent flight when hunting insects. Barn owls for example, are seriously inconvenienced by rain because the water soaks the wing feathers and makes silent flight impossible. It also dampens long grass making take off after a dive very difficult.

Chris also suggested several rules for successful owl watching. Dark, quiet clothes are a basic necessity together with lightweight binoculars which are effective in low light, for example 8x40. It is advisable to get to know the area in daylight and establish suitable areas of habitat that the birds are most likely to hunt. If the area is being used as a roost, you must not disturb it, but make sure you watch from a safe distance. Try to arrive at your observation position before dusk, as this will allow your eyes to become accustomed to the growing darkness, and allow you to settle yourself before the owls emerge. You must make sure that you do not disturb the birds in any way, and if you find that you have accidentally chosen a spot too close to the nest, move swiftly and quietly away. It is important to consider your safety when owl watching, particularly as most of the observations are likely to take place at night. An efficient torch is a` must’, and don’t forget to tell someone where you are going. If you choose a site on private land, don’t forget to seek the landowner’s permission, especially if you are likely to be there at night. A mobile phone, fully charged, is also a necessity, and keep to footpaths or public land where possible. Finally, keep to the Country Code.

I am sure that everyone learnt a great deal and thoroughly enjoyed the evening.

Jo le Roux